Field of the Invention. The present invention generally relates to vacuum operated milking machines and in particular those vacuum operated milking machines which utilize a rigid shell and a flexible inflation or liner.
Background of the Invention: Modern agriculture combines the use of technology with traditional farming practices to achieve greater yields in the production of food and crops. In the dairy industry, the mechanization of the milking process through the use of so called milking machines has been one of these great advances. These milking machines come in a variety of configurations, however one predominant configuration employs the use of a vacuum connected through tubes to a plurality of teat cup assemblies. Each of these teat cup assemblies is typically made up of a rigid outer shell which is hollow and a resiliently flexible inflation or liner portion which is configured to fit within the hollow rigid outer shell portion.
A typical milking assembly is made up of a device called a claw from which four milking cups extend. Each of these milking cups contain a rigid shell and a flexible inflator. These rigid shell portions are typically made from a strong rigid material such as stainless steel, which is able to withstand the force of the milking parlor including occasionally being kicked or stepped on by a cow. These rigid hard shells contain a tube for connection with the pulse system and an aperture through which a portion of the inflator called the short milk tube extends. This short milk tube is connected to the short milk tubes from the other three milking cups at the claw and a long milk tube extends from the claw to a collection device such as a tank at a distant location. The pulse system is also similarly connected to a long pulse tube, which provides the pulsing vacuum pressure to the milking cup. When the milking cup is connected to the pulsing system the pulsing system applies a vacuum at selected intervals. This alternating application of vacuum pressure through the tube causes the liner to alternatively constrict and relax its position around the teat. This alternative constriction and relaxation causes the liner to rhythmically pulsate, simulating the sucking of a calf upon the teat. This variation in the constriction of the teat by the liner causes milk to flow from the teat and to be collected through the milk tube lines.
The inflations or inner liners are typically made up of a tubular liner portion having one end configured to engage and hold the teat portion of an udder within the device, and a second portion which extends through the hard shell cup portion so as to hold the liner within the milking cup. This inflation is typically made from a resilient but flexible material such as rubber or plastic compositions which are resistant to tearing or cutting by impact. These liners or inflations are the only parts of the milking device which actually come into contact with the animal. Studies have shown that the configuration, construction, fit and placement of the liners upon the teat has a greater effect than almost any other factor in the efficiency of the milking process.
A variety of configurations, designs and formulations for teat liners have been invented. Examples of these various devices are found in U.S. Pat. No. D480,184, U.S. Pat. No. 5,007,378, U.S. Pat. No. 4,315,480, and U.S. Pat. No. 4,459,938. While the configuration and exact placement of these devices varies, all of these liners must be designed to provide certain features. These features include: the ability to provide an airtight joint at both ends of the shell, provide a mouthpiece and a barrel which fit on to the teat to minimize the slipping of the liner and the milking cups, and allow the claw of the milker to be interconnected to a designated location.
Regardless of the type of material that the liner is made from, no teat liner can last forever. Over time these liners will wear out, break or otherwise become useless. In addition, various modifications made to the liners may also cause the dairyman to wish to change out the liners which are in their milking cups.
The frequency at which such a replacement must take place is dependent upon a variety of factors. However, it is estimated that a typical liner will function within a milking machine for approximately 900 to 1800 milkings. After this quantity of milking these liners must be replaced. On the average most milking cup liners must be replaced at about 1200 milkings. Depending upon the size of the operation in which the device is being used, this means that these liners would have to be replaced approximately every 2-3 weeks. In as much as each milking station would require a replacement of 4 such liners, an operation that utilized 50 milking machines would have to replace 200 liners every two or three weeks. This process is typically done by hand and can be quite time consuming and expensive.
In order to insert the inflations or liners in to proper position within the rigid milking cup, the short milk tube portion of the liner must be pulled through an aperture of the base of the rigid milking cup. When the inflation is so positioned, the head of the liner covers the top portion of the rigid cup and the short milk tube is pulled through this smaller aperture at the base of the rigid milking shell. In order to remove the liner from this position, the liner must be pulled with sufficient force so as to pull this rear lip back out through the aperture and remove the liner from its location within the milking shell. Once these liners are removed, the old liners can then be thrown away and a new liner inserted into the hard shell milking cup and pulled through this smaller aperture.
In as much as the configuration of the materials which make up the liners vary, so also the flexibility varies between the liners themselves. This difference in flexibilities at times can be so great as to prevent a party attempting to insert or remove these liners from being able to adequately perform this task. Therefore what is needed is a device which is simply easier to use and which allows an operator to selectively place and remove liners within hard milk shell casings with increased efficiency as compared to currently existing methods which is listed in the prior art. What is also needed is a device which enables a user to simply and effectively remove and insert liners from within the milk casing and hard shell liners. Accordingly, it is an object of the present invention to provide a simple device to operate and to enable a user to selectively insert and remove plastic shell liners from within a hard shell milk cup device. An object of the present invention is to provide a device which will enable a user to place and remove these plastic shell liners from within a hard cup device.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.